Jail-door alarm



(No Model.)

W.v S. HULL. JAIL DooR ALARM.

No. 494,923. 'PatentedApL 4, 1893.

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f l i UNITED STATES PATENT OEEICE WILLIAM S. HULL, OF. SHEFFIELD, ALABAMA.

JAlL-DOOR ALARM.

SPECIFICATION forming part of Letters Patent No. 494,923, dated April 4, 1893.

Application filed September 19, 1892. y Serial No. 446,339. (Nomudel.) i

ing had therein to the accompanying draw-Y ings.

This invention has for its objectsA among others to provide a simple and cheap and etticient jail door alarm which can be readily ap# plied to any jail cell door, or other door, and

so arranged that the jailer will be warned when the prisoners tamper with the doors and also give'him warning when handling prisoners if any of the doors are open. Thus, if he should want to feed the prisoners, at night and the lights are dim the prisoners cannot play tricks on him by slamming the doors, when ordered, and then pushing it slightly ajar so that when the jailer throws his lever bolts from the outside they pass behind the door instead of over its face and thus leave the door unlocked so that when the jailer opens the corridor door and goes in they can rush upon him and overpower him and escape. This is prevented because unless the door is closed tight the bell will continue to ring and thus warn the jailer. When the jailer desires to lgive the prisoners access to the corridor he can turn the switch and thus stop the ringing of the alarm.

In itspreferable form the invention comprises a crank` rod or arm connected with the door at the hinge side and suitable devices actuated by this crank rod through the movement ot the door to sound an alarm. The movement of this rod will inuence an electric current, by closing the circuit when the door is open and opening the circuit when the door is closed.

The invention embodies. simplicity of construction, ease of application and efticiency in operation, with durability.

Other objects and advantages of the invention will hereinafter appear and the novel features thereof will be specifically defined by the appended claim.

The invention is clearly illustrated in the accompanying drawings, which, with the let- 'door rod or arm just leaving the push button.

Like letters of reference indicate like parts in both of the views where they appear.

Referring now to the details of the drawings by let-ter, A designates a door of 4usual cohstruction hung upon Vhinges as c., and while l have shown but one door it will ot course be understood that a plurality of them may be arranged as is usual iu jails and all locked by the turning of a single lever, but as the manner of locking forms no part of this invention I have chosen to show but one door and have omitted the locking means.

On the hinge-side of each cell door is attached in any suitable manner a crank-rod B, B which projects above the top of the door into a box or casing (not shown) in the corridor where there are two or more tiers of cells, and where there is only one tier of cells the rod should project through the top of the corridor into a metallic box or casing. The crank portion of the rod isabove the ceiling or upper door as seen in Figi.; it is designated by the letter B.

Upon reference to Fig. 2 the electrical connections will be readily understood. In this view C designates the battery, D the bell, E the automatic drop and F the switch, all of known or any approved form of construction. They are connected up in the proper manner by the wires which, in practice, although not so here shown, are designed to be incased in suitable metallic pipes or other coverings.

G is a contact plate suitably supported and having connected therewith the wire g which extends to the bell D and by a branch wire b is connected with one pole of the battery as shown.

H is a spring plate connected by the Wire h to the switch from which wire h extends to the automatic drop E and the drop is, by a wire h2 connected to the other pole of the bat- ICO 'dlap the end of the contact plate G as shown in Fig. 2. The end of the push button projects beyond the face of the spring plate in position to be engaged by the crank rod or arm B When the door is closed which depresses the push button and plat-e .I so that the latter is out ot' contact with the plate G.

The operation of the electric devices shown in Fig. 2 is as follows: When the door is opened, even to a very slight extent, the spring plate H brings the plate J into contact with the plate G; this closes the circuit and the current produces an alarm at the bell and at the same time releases the automatic drop whereby the bell remains in circuit extending through the conductors B and G from the battery to the bell, shunt Wire b and wire hzfroxn the bell through the drop back to the battery. This although the door may be again suddenly closed so as to throw the plate J out of contact with the plate G the bell continues to.

sound an alarm, notwithstanding the breaking of the circuit by thus closing the door, and

the alarm will continue to sound until the automatic drop is raised to cut the battery out of circuit. The switchJ servesits usual function to throw the electrical devices temporarily out of use When desired.

The construction and arrangement ot` parts above described constitutes the preferable form of my invention but I do not confine myself to the exact form shown as I have already devised other forms which, While differing slightly in details, operate in substantially the same manner to accomplish thesame result.

It will be seen by the description above given of the construction and arrangement employed that none of the exposed parts are capable of being manipulated by a person so as to make 'or break the electric circuit to prevent or produce an alarm. The rod B and its arm B are situated beyond the oor or ceiling and are not electrical devices so that the exposed part of the rod cannot possibly be made the instrument of communication with the devices which affect the circuit controlling devices. f f

I am aware that spring contact plates are of themselves, old devices and have been applied to doors and Windows in such manner that the opening of the same will complete an electrical circuitand sound an alarm but such devices have been placed in positions Where the introduction of a thin metallic blade or wire could be accomplished so as to produce an operation of the alarm.

In jails, prisons and-fthe like structures. the

`combination with a door'having a rod as B projecting from and substantiallyin line with its hinge line and provided with an arm located at a point inaccessible from the door, of

a spring plate carryinga pushV button normally held by said plate in contact with-said arm when the door is closed, al contact plate carriedy by the push button and normal-ly held by said contact plate, with acompanionplate and an open electrical circuit having therein `an alarm and an automatic` drop connected with each other and with the battery which is in said circuit, substantially as specified.

In testimony whereof I affix my'si gnature in presence of two Witnesses.

WILLIAMS. HULL. Vitnesses:

` J. M. PINKsToN,

HERMAN F. JONES. 

